The Car Thread

[Elliot]

Hey, I have an inquiry:
One of my projects is to invent The Ideal Transmission for my pedal-vehicles. This will be a chain gang, somewhat like used on some British "cycle cars" of old. I think I have the design figured out -- except for the control mechanism. Or... actually... the tried-and-true automobile four-speed H-pattern floor-shifter would serve well, if it were scaled down. And actually, I only need four positions, so a 3-speed shifter would do (using reverse for the fourth position).

(Yeah, you are all thinking "Hurst" right now.)

Sure, I could fabricate 20 (eventually) of these. But time is precious. Maybe they are out there? Ford Pinto? A lawn tractor?

[ygmir]

Hey, I have an inquiry:
One of my projects is to invent The Ideal Transmission for my pedal-vehicles. This will be a chain gang, somewhat like used on some British "cycle cars" of old. I think I have the design figured out -- except for the control mechanism. Or... actually... the tried-and-true automobile four-speed H-pattern floor-shifter would serve well, if it were scaled down. And actually, I only need four positions, so a 3-speed shifter would do (using reverse for the fourth position).

(Yeah, you are all thinking "Hurst" right now.)

Sure, I could fabricate 20 (eventually) of these. But time is precious. Maybe they are out there? Ford Pinto? A lawn tractor?

my army Mule has a small transmission, 3 speed w/reverse. Maybe google parts? Or the trans from an old Honda 70 or 90 (high/low range besides). Light weight, progressive shift.

[Elliot]

Does the Mule have an external shifter with two levers protruding at the bottom, like Detroit muscle cars of yore? Even if so, I cannot imagine they are readily available, and cheap?

Alas, I wish I could use motorcycle transmissons. But I have tried this, with little luck. First I removed the engine-end of 4-stroke engines and just left the tranny open to dirt. This functioned, so I went to 2-stroke engines where a sealed case remains around the tranny after cutting off the engine. But it is a rather clunky solution. Finally I bought vintage BMW "airhead" transmissions at $400 a pop -- and repeatedly broke them. They also weigh 25 pounds a piece.

In each case I installed two trannies in series to get a wide enough span of ratios. The sport actually calls for even wider span -- three trannies in series!

So I want to try chain gangs, which have essentially no limit to ratios other than ground clearance. But friction may be an issue.

The numbers? Cars, motorcycles, and bicycles typically have somewhere around 300% or 400% span between lowest and highest ratios. In Kinetic Sculpture Racing we need something like 1,500% or more.
On my "Pear County Chopper" -- the green tricycle I've been powering thru mud with recently -- there are two transmissions, each with 350% span. 350% x 350% = 1,225%. That's not bad, but not quite enough.

Oh... what's with the low/hi on those old Hondas?

Here is the piece I'm looking for, but smaller and lighter, and readily available for cheap from wrecking yards and such. It's the lower half that matters -- the upper half is just a stick. This one goes on muscle-car-era Chevy Novas and Chevelles and such.

[ygmir]

yeah Elliot, on the old Honda CT90's it had a true high/low range selector, then 4 speeds 1 reverse.
my playa bike has a 3 speed transmission, in the rear hub. That might get you a ways without having too many chain and sprocket combo's.

could you make a transmission, like a centrifugal one, like a snow mobile or old mini bike? cones and graduated shiv wheels, where as you sped up, the gearing gets higher? or, like on my old Bobcat,where you had a lever to change the distance between graduated drive disks, so that closing took it further to the outside of the disk, and vice versa for high/low? sort of infinat gears, as such.
a lever and lock mechanism does the trick for spacing and setting said space.

[Elliot]

.
I will certainly try to find the ratios in the CT90.

Three-speed bicycle rear wheel hubs -- pioneered by Sturmey-Archer of England, who long dominated that market -- cannot take much more than normal bicycle loads. Believe me, I have tried them. The first time I shifted one "in anger" the wrist-watch-size planetary gears turned to dust. (Wrong kind of dust!)
Shimano makes such hubs now with as many as 9 gears, and I'm sure they are stronger, but I was breaking BMW motorcycle trannies.

The two trannies on Pear County Chopper are a unique brand of bicycle rear wheel hubs called NuVinci. They are also suitable for small motorcycles. The factory gave me two of them to "try to break them". I have "failed". But there is a lot of friction in them, and I would ultimately need three for each rider. And the factory is not going to keep giving them to me for free. So, not realistic.

Centrifugal, Constant Velocity Transmission (variable cone diameters with V-belt), variable friction disc.... All considered, I think.
I don't need a clutch.
CVTs work great in cars, and you can buy them in some modern cars. In Norway I owned a Dutch-made DAF with CVT and loved it. But too much friction for human power.
Not familiar with the Bobcat tranny, but step-less friction discs were used on early cars -- 100 years ago. Again, too much friction loss for human power.

A combination of transmission-types is realistic. I could add a bicycle derailer to the first stage on the Chopper -- that is, at the input of the first NuVinci. But I'm trying to standardize all this with an easy-to-operate system so anyone can jump on and ride any of these machines.

That said, four shifter-positions in series would be even more instinctive than the H pattern. But my design of the chain-gang pretty much relies on the neutral cross-over position just like a traditional car tranny. Oh, I have studied motorcycle ratchet shifters too! But at this stage I thought I'd look for something out of Chevy Vegas or some such readily available junk.

To clarify the Basic Concept: There are at least five machines that need this "Holy Grail" transmission, with up to five riders each. And each rider is to have his own tranny, to avoid the need for coordinating shifts. So I may eventually need something like 25 trannies. Yeah, I'll die of old age first, but....

[ygmir]

so, in simple terms, you have 5 riders, each with a chain to the drive axle, and you want the to be able to vary their speed/effort at will, but still be able to add input to the drive system?

[Elliot]

You are correct, the riders will need to be in approximately the same gear, or some will not be able to contribute. But people have different pedaling habits. Some are "spinners", meaning they pedal fast with low torque, say 80 RPM. Others, like me, are "stompers" and are happier at 65 RPM. With two or three bicycle derailer arrangements in series, such fine-tuning is normal.

This however, is NOT an issue in my scheme. This proposed arrangement has only four gears, and they are very wide apart in ratios. So no slight variation in cadence will be possible. This is an acceptable tradeoff for having a fool-proof system. Most of the problems Kinetic racers have along the route involve bicycle-size chains and derailer stuff.

So the idea is to use only four gears, but build them bomb proof. Motorcycle chains. Yes, all the riders will need to get into the same gear as the terrain changes, but they will be able to make the shift un-hindered by the others. See... it is difficult to get two people to synchronize their shifts, specially if they are not familiar with the machine. And then one would not be able to shift while the other is still pumping. So we want none of that "Ready for downshift, three, two, now!" Then "Wait everybody, I got stuck!"

One rider, one transmission. If one rider shifts early or late, no harm done to the others. That's why 25 trannies, eventually.
Also, with the reductions we use, one person can generate enough torque to break some serious steel. I've seen two people tear a #40 chain (small motorcycle) in half. And I had four people shatter a pretty stout-looking differential out of some industrial machine. So it is best to split them up -- one rider, one tranny, one wheel. Also allows the machine to shrug off any one mechanical failure.

The picture show "Henry Ford Goes Surfing" a few years ago. Four completely independent drivetrains, each rider to his own wheel. Pretty much unstoppable, except that the trannies were inadequate.

[ygmir]

is there a way to put them all on the same shaft, and then have gears from it to the drive?
then each have a choice to that shaft, but the "driver" would pick the gear,drven shaft to drive shaft?

[Captain Goddammit]

There's one up here that is like that. Ten pedallers hooked to a common shaft, on what appears to be something like a Toyota 4 wheel drive truck chassis. I think it has it's original transmission and transfer case. It made the beach sand course look as easy as idling a car across a parking lot, but to my surprise, it was a fail in the mud bog, because it was too heavy. But nothing broke, with ten pedallers and lots of resistance.
It seems a conundrum, making it heavy duty, but not heavy.
I wonder if you could get your hands on some differentials from a 4x4 quad, like a Polaris or something. I had one, 700cc fuel injected 4x4 that really had power, those parts seem like about the right scale.

[ygmir]

you could use the old CT90 trans by extending the crank shaft out the side of the case, hooking on where the centrifugal clutch would normally be, and have the sprockets on that input shaft. Then you'd have High/Low and 4 speeds.......and with it being about a 5 h.p. engine, the drag should be pretty low. Only issue would be reverse, I suppose, if you were using derailleurs and chain drive from pedalers to input. They could have their own gearing between pedals and shaft that way, and overall gearing could be controlled by the pilot, as relates to vehicle speed/torque. even only a 3 speed rugged trans, from pedaler to input shaft, would allow for variance in individuals, no?

[atomicray]

You are correct, the riders will need to be in approximately the same gear, or some will not be able to contribute. But people have different pedaling habits. Some are "spinners", meaning they pedal fast with low torque, say 80 RPM. Others, like me, are "stompers" and are happier at 65 RPM. With two or three bicycle derailer arrangements in series, such fine-tuning is normal.

This however, is NOT an issue in my scheme. This proposed arrangement has only four gears, and they are very wide apart in ratios. So no slight variation in cadence will be possible. This is an acceptable tradeoff for having a fool-proof system. Most of the problems Kinetic racers have along the route involve bicycle-size chains and derailer stuff.

So the idea is to use only four gears, but build them bomb proof. Motorcycle chains. Yes, all the riders will need to get into the same gear as the terrain changes, but they will be able to make the shift un-hindered by the others. See... it is difficult to get two people to synchronize their shifts, specially if they are not familiar with the machine. And then one would not be able to shift while the other is still pumping. So we want none of that "Ready for downshift, three, two, now!" Then "Wait everybody, I got stuck!"

One rider, one transmission. If one rider shifts early or late, no harm done to the others. That's why 25 trannies, eventually.
Also, with the reductions we use, one person can generate enough torque to break some serious steel. I've seen two people tear a #40 chain (small motorcycle) in half. And I had four people shatter a pretty stout-looking differential out of some industrial machine. So it is best to split them up -- one rider, one tranny, one wheel. Also allows the machine to shrug off any one mechanical failure.

The picture show "Henry Ford Goes Surfing" a few years ago. Four completely independent drivetrains, each rider to his own wheel. Pretty much unstoppable, except that the trannies were inadequate.

Here I was reading the last handful of posts and was thinking that this was in the realm of bonkers and then the picture brought it all home.

It seemed like a lot of extra complexity for complexities sake alone...now I have a much better idea of what is desired...funny how meaningful a picture can be

[Elliot]

.
Same "car" at Port Townsend, WA. This is the mud pit where we shattered the differential on an other four-seater.



Note cleats strapped to tires, like snow chains. Yes, we got thru. Yes, I'm steering from the back seat.


About the 10-seater the Captain saw up there, I know of two that fit this description.
One lives in Eureka, CA, and is a Ford pickup chassis on Hoosier auto racing tires like I use. The weird thing about it is that the riders face outward, five to each side. It usually has artwork on top.
The other is in Corvallis, OR, and is based on two front axles from a small 4x4 (it steers at both ends!) -- I cannot for the life of me think of the name now. Tiny 4x4. Wheels and tires are farm tractor type. Here the riders face inward, and they push "treadles" rather than bicycle pedals. It has a deck on top, for the accordion band.
Both were on Playa in 2010, with Kinetic Cab Company. Yes, I had something to do with that.

As for extending a motorcycle crankshaft to use as input to the tranny, I have one like that in my barn, safely discarded. (Actually, no extension was needed.) It came with a vehicle I "inherited" because it did not work. Trouble with that particular item is that there is a huge down-gearing between the crankshaft and the tranny. On a different unit I counted 1:60. Humans cannot pedal 4,200 RPM! So on the ones I used, I went directly to the tranny input, where the clutch used to be. On the BMWs, I had to find used clutch discs and weld sprockets to the disc hubs.

This idea of running all the riders onto one shaft.... I don't quite follow that. (But I call that a collector shaft.) But I have a vehicle here (same as the one just mentioned) with exactly that, where the power from all four riders goes into one shaft, and then one chain from there to the one drive axle -- with a transmission in between. On this, we tore the #40 final drive chain in half coming up a boat ramp, and later tore the mounting ears off a cast iron flange bearing in the transmission. I'm in the process of splitting that drivetrain in two.

We have used diffs, and whole transaxles from lawn tractors and such. Trouble with those transaxles, again, it that we would need two or three in series for enough ratio spread.

One type of tranny that works well, is more of a method than a tranny. There is an input shaft and an output shaft, with their respective sprockets. On the "operational" side we have two-sprockets-and-a-chain, which can be quickly slid off their shafts and replaced with a different set. This is what I've been using on this vehicle lately. (I'll find a picture of it.) I had three of four (at different races) sets of "gears", and I had it down to 2 minutes to make the swap, with the others handing me parts and tools. It can work great, except that you have to stop a while to do it.

Yes, this is GREAT fun!

[ygmir]

could you not gear the common shaft, before it goes into said motorcycle transe up, so as to offset your 60:1 sprockets or whatever?
do you ever use a heavy flywheel?

[Elliot]

.
This is the kontraption I was just talking about....




Here as I received it, and that's about how far they got with it.





Then on Playa a year or so later (without yellow cloth “body” and amphibious equipment), converted to three wheels -- larger ones -- and with transmission improvements.





Finally with blimp body even later, featuring our own Gaminwench as co-pilot.

[Elliot]

could you not gear the common shaft, before it goes into said motorcycle transe up, so as to offset your 60:1 sprockets or whatever?
do you ever use a heavy flywheel?

That's what the original builders did. You should have heard that thing screeeeaaam like a chain saw as the speed increased -- what little it increased.

No flywheels. Weight is the enemy.

[Elliot]

Here's a chain gang transmission. Fraser-Nash, possibly. It's a four speed -- one of the chains can be reversed for... uh... reverse.
There is no diff, only a ring-and-pinion. I guess English country roads were not paved in those days.





This is the shifting mechanism, Dog help me.

[atomicray]

Call me crazy, but this fills me with a tinker's joy!

I would love to have that in my shop at this very moment

[Elliot]

.
Yup. And we are finally back to real automobiles!

[name redacted]

I was at the vintage automobile races at Laguna Seca many years back. The picture above reminds me of a 3 wheeled racecar that had a harley engine mounted in front of the front wheels.

[Elliot]

I was at the vintage automobile races at Laguna Seca many years back. The picture above reminds me of a 3 wheeled racecar that had a harley engine mounted in front of the front wheels.

That was probably a Morgan, many of which had J.A.P. (J. A. Prestwich, I think) engines. All very, very British. (In recent years Morgan has tried to launch a replica with a Harley type engine.)

Overnight I came to think of a picture...



What's happening here is an emergency repair during a Kinetic race in Corvallis, OR. This is one place we tore the #40 final drive chain in half. Here I am adding bungee cords to a chain tensioner, to -- hopefully -- cure a chain-skipping problem, while Glorious Spectators wait patiently in background. Photo by Tina Kerrigan Photography.

The shiny square box is the transmission where we quickly swapped out sets of two-sprockets-and-a-chain, located on the other side. You can see the output chain, the final drive to the rear axle, which we tore in half.

[ygmir]

what I'm seeing there, Elliot, is you taking the submissive/missionary position, with an ominous looking buzz sawish (sprocket) set to punish you........are you sure of your story?

[FIGJAM]

I thought it was 007.

[Captain Goddammit]

I'm almost certain that bare chassis with the chain gang transmission is indeed a 1930s Fraser-Nash.
The very noticeable positive camber of the front wheels is a particular trademark of those cars as well as the chain drive setup.
Also the unusual early overhead valve engine is something often found in a Fraser-Nash... although an F-N isn't often found at all.
Cool shot, I've never seen one with the body off!

[atomicray]

Can that be Elliot?

I mean this person is wearing clothes

[name redacted]

Elliot, when will you be around so cal again? I think you were in ventura last week, but I couldnt make it. Anything in norcal in your future? Would love to wrench with/for you in a race!

[Elliot]

what I'm seeing there, Elliot, is you taking the submissive/missionary position, with an ominous looking buzz sawish (sprocket) set to punish you........are you sure of your story?

The buzz-saw-blade that is about to lose all its teeth in a doomed attempt to castrate me... is one of the two sprockets that drive the paddle wheel, which hangs off the back of the axle. There is no chain on it, because we are on land.

The near disc, with a bunch of "22" holes in it, is the brake rotor.

Yes, I raced in Ventura on October 19. Was awarded Best Engineering. But that was the last race of the season. Next race is in Northern California in late May.

Yeah, I'm wearing clothes.
It is sort'a expected in the sport, it being held in public streets.

But I'll tell you a story: That ten-person vehicle that Goddammit saw in Port Townsend.... Two or three years ago it raced "naked" in the Grand Championship -- 40 miles over three days. This was the work of a splendid artist in Eureka. First, she made a giant replica of Michelangelo's David, out of styrofoam and fiberglass ( I guess), for a theatrical stage production. After the play closed, David was too good to just toss aside. So she tailored ten skin-colored body-suits for the ten riders (which included herself), then air-brushed "anatomically correct" features on the suits so they all appeared quite realistically naked.

David was hoisted on top of the machine. He could pivot, to lay down for clearance under bridges and wires, and in strong wind. The rest of the time he stood upright.

So there was this 12 foot naked marble man, being propelled down the street by ten live "naked" people. It was fabulous, but there were still a few bible-thumpers who complained it was obscene.

(Google "Kinetic Sculpture Race" "Classical Nudes" for photos.)

[Elliot]

I'm almost certain that bare chassis with the chain gang transmission is indeed a 1930s Fraser-Nash.
The very noticeable positive camber of the front wheels is a particular trademark of those cars as well as the chain drive setup.

And why the pronounced camber angle? Yes, this is a test. (Clue: Most early cars had it, to lesser or greater extent.)

[FIGJAM]

My guess would be to make them "track" better.

[shroom]

2010 Chevy Camaro SS. I love my car. Her name is Jolene.

[Captain Goddammit]

I don't know for sure why the positive caster on the old cars, over the years I've heard it was because the roads had high crowns (I don't buy that) to bump-steer issues and bearing loading issues.
I know it didn't matter as much if the tires were slanted because the tires were similar to motorcycle tires back then.
But I really dunno exactly for sure what's up with it.